819997258369 has 9 divisors (see below), whose sum is σ = 839550310113. Its totient is φ = 800889522132.

The previous prime is 819997258337. The next prime is 819997258387. The reversal of 819997258369 is 963852799918.

The square root of 819997258369 is 905537.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 819997258369 - 2⁵ = 819997258337 is a prime.

It is a super-2 number, since 2×819997258369² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 819997258295 and 819997258304.

It is not an unprimeable number, because it can be changed into a prime (819997258309) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 38927562 + ... + 38948620.

Almost surely, 2^819997258369 is an apocalyptic number.

819997258369 is the 905537-th square number.

819997258369 is the 452769-th centered octagonal number.

It is an amenable number.

819997258369 is a deficient number, since it is larger than the sum of its proper divisors (19553051744).

819997258369 is an frugal number, since it uses more digits than its factorization.

819997258369 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42204 (or 21102 counting only the distinct ones).

The product of its digits is 529079040, while the sum is 76.

The spelling of 819997258369 in words is "eight hundred nineteen billion, nine hundred ninety-seven million, two hundred fifty-eight thousand, three hundred sixty-nine".